Eco‐friendly synthesis of Ca‐ and Mg‐doped ZnO nanoparticles via Ferula halophila : Photocatalytic and biological activities

Abstract The application areas of nanoparticles have increased significantly in recent years. Their use in composite or doped forms has become widespread to impart specific functional properties to the base material or to improve its existing properties. In this study, pure ZnO, 5% Ca‐doped ZnO (Ca:ZnO), and 5% Mg‐doped ZnO (Mg:ZnO) nanoparticles were synthesized via a green synthesis approach, which offers advantages such as the use of non‐toxic chemicals and low cost. The morphological, optical, and structural properties of the synthesized nanoparticles were characterized using Ultraviolet–Visible Spectroscopy, X‐ray Diffraction, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, and Energy Dispersive X‐ray Spectroscopy. The effect of dopant elements on the ZnO structure was also evaluated. According to the photocatalytic results, the degradation efficiencies of pure ZnO were 87.27% and 79.66% for tetracycline and aspirin, respectively, while those of Ca:ZnO were 90.53% and 86.44%, and those of Mg:ZnO were 89.94% and 98.30%. In antibacterial tests, all samples showed activity comparable to control antibiotics; the highest activity was observed for Mg:ZnO (0.716 cm for S. aureus , 1.517 cm for E. coli , and 1.397 cm for P. aeruginosa ), while the highest activity against K. pneumoniae was observed for pure ZnO (1.110 cm). The cytotoxicity assay demonstrated that the Mg:ZnO formulation exhibited the lowest IC 50 values, specifically 51.66 μg/mL for HNSCC, 71.31 μg/mL for PANC‐1, and 37.07 μg/mL for HepG2. Overall, the findings indicate that Mg doping significantly enhances the photocatalytic and biological activities of ZnO, and the synthesized nanoparticles exhibit strong potential for environmental and biomedical applications.